1. Field of the Invention
This invention relates to connecting elements more particularly to a connector for securing components of inflatable structures or membranes together.
2. Discussion of the Prior Art
It is known in the prior art to construct inflatable members or components that are impervious to air and water. In order to form useful inflatable structures, such as life rafts and evacuation devices for commercial and military aircraft, two or more inflatable members, as well as non-inflatable members such as floors and support webs, are typically joined together.
An example of a prior art arrangement for joining inflatable members together is illustrated in FIG. 1. An inflatable structure 10 of a prior art floatation device, such as a life raft, is schematically shown in cross section. The inflatable portion 10 includes a lower inflatable tubular member 12 and an upper inflatable tubular member 14 that is joined to the lower tubular member at a connection joint 16. Each tubular member 12, 14 includes a wall 18 that is impervious to air and water. The connection joint 16 has an area of adhesive 20 between the tubular members and a crotch tape 22 located on opposite sides of the tubular members. The adhesive bonds the tubular members 12, 14 together and bonds the crotch tapes 22 to the walls 18 of the tubular members. Each crotch tape 22 can be constructed as a single piece of material which is bent to form a V-shape member. The crotch tapes 22 serve to enclose the adhesive area 20 and prevent separation of the tubular members 12, 14.
Although this type of structure is currently in use, it has been found that the connection joint is prone to leakage, especially at the ends of the inflatable structures where overlapping joints are common. Thus, when the inflatable portion 10 is part of a life raft, sea water can leak into the connection joint 16 and compromise the integrity of the structure.
In addition, as shown in FIG. 2, the prior art connection joint 16 is subject to a peeling mode of failure, which tends to separate or dismember the joint, and thus the inflatable elements and/or panels connected at the joint. The peeling mode occurs, for example, when a tensile force is applied to the leg 24 generally in the direction of the arrow 28. When this force is applied, the leg 26 will tend to separate from the wall 18. The same peeling mode exists in structures where a panel, such as a floor panel of a raft, is directly bonded to an inflatable member or other panel. For a used fabric utilized in the filed of inflatable structures, it has been found that the panels or walls tend to peel apart with an applied force of approximately 7 pounds per square inch (psi).
The above-described problems are further augmented by the long curing time of adhesives used to bind the panels together. The formation of each connection joint is labor intensive and requires the application of a suitable layer of adhesive between overlapping areas of the walls, tape and/or panels. Each joint must be formed separately and typically must be cured for at least four hours before forming a subsequent joint. Thus, much manufacturing time is lost due to the long curing process and human error can be a substantial factor since much of the bonding technique requires human intervention. Other prior art connecting joints are illustrated in FIGS. 12 and 15 and will be discussed in full detail later in the application.